Sinker for selection and control of loop-forming movements of knitting implements of a knitting machine

ABSTRACT

A control plate (17) for selecting and controlling knitting movements of tools in a knitting machine driven by the relative movements of the plate support (11) and a cam support (12), in which the control plate can be forced into an engagement position of a drive output foot (61) of the control plate with an output drive edge of an output drive component (73) to transmit the deflection drive by the action of a minimum pre-tension of an extended rod-shaped control spring (37), the free end of which is supported to slide on the base of a guide groove (16) accepting the control plate, is constructed as a one-piece spring steel component to simplify manufacture and increase its wear resistance, in which its width (h) measured perpendicularly to the neutral elastic line (54) of the control spring (37) at the base side of the spring at which it bears on the basic body (18) of the plate is greater than at the free end (48) of the spring by which the spring is supported on the base (25) of its guide groove (16), where the spring (17) bears on the basic body of the plate via a smooth curve widening the base region.

FIELD OF THE INVENTION

The invention relates to a sinker for selection and control of theloop-forming motions of knitting implements of a knitting machine towhich is assigned a sinker which has the form of a flat bar according tobasic shape as the control element which can be deflected in a guidegroove of a sinker carrier in its longitudinal direction in alternativedirections of movement

BACKGROUND AND SUMMARY OF THE INVENTION

In these knitting machines, for example, circular knitting machineswhich have a cylindrical sinker carrier which can be driven to rotatewith vertical run of its central axis around it and which is locatedwithin the stator of the machine which has the form of a cylindricaljacket according to external shape and which coaxially surrounds thesinker carrier, the sinker carrier contains a plurality of sinkers, forexample 2000 which are located next to one another in edge-open radialgrooves which are equidistant in the azimuth direction, with a verticalrun which is parallel to the center longitudinal axis of the platecarrier, in each of these grooves being a sinker which can move up anddown.

For controlled driving of the sinkers in this regard, which takes placeby relative rotational movements of the sinker carrier to the machinestator which is made as a cam carrier, the sinkers are provided withclearing feet which have contour edges which run transversely to thesinker guide direction; by their sliding away the deflections of thecontrol sinkers are controlled via a drive cam of the stator providedwith a clearing edge. In this case the control sinkers, by the action ofa minimum prestress per control spring which proceeds from a base bodyof the sinker and which has a stretched rod shape in terms of basicshape, and which has a free end which is supported to slide on the baseof the guide groove of the control sinker, are displaced into theengagement position of their clearing foot which transfers deflectiondriving, with the clearing edge of the clearing cam of the cam carrier.They can furthermore be displaced by control elements of the cam carrierand sinker carrier which work by force fit-form fit into a baseposition, in which the drive engagement of the clearing feet iscancelled with the clearing edge of the clearing cam. In this baseposition the sinkers can be fixed by the retaining force of a permanentmagnet arrangement which has a holding action which can be cancelled bycompensatory triggering of an electronically controllable magnetarrangement, so that the sinkers can be released by the action of thecontrol springs for assuming the clearing position.

In known sinkers of this type (DE-39 15 684 C1) the control springs aremade as spring steel rods with a cross section which is round,rectangular or uniform over its entire resilient length and withflattened anchoring pieces which are rectangular, flat-plate formedaccording to basic shape, and which has a thickness which is less thanthat of the sinker material which is equal to the diameter of the springleg measured at a right angle to the longitudinal surfaces of thesinker, in flat groove-shaped depressions with cheek contour which ismatched exactly to the contour of the anchoring pieces, anchored byforce fit-form fit, the resilient rod passing through a short opening ofthe sinker material which discharges into an anchoring depression. Tosecure the spring rod against disarrangements in the anchoringdepression of the sinker, on the edges of the depression which theanchoring section of the spring rod adjoins, there is caulking of thesinker material which in interaction with notches of the anchoringsection yields a force-fit/form-fit connection of the spring rod withthe sinker overall. The spring rods are fixed on the sinkers such thatthe center longitudinal axes of the spring rods run in the longitudinalcenter planes of the sinkers which extend between their large area shaftboundary surfaces.

The known sinkers are subject to at least the following disadvantages:

Production of the sinkers is complex and expensive, since the anchoringdepressions of the sinkers and the anchoring end pieces of the springelements must be matched to one another within narrow tolerances; thisrequires high-precision machining of the surfaces which touch oneanother. Joining of the sinker elements to be connected to one anotherrequires time-consuming mounting effort which for its part is costly.Finally the caulking of the edges of the anchoring grooves of the sinkerbase body with the edges of the anchoring pieces of the springs in manycases can lead to undesirable bulges of the sinker shaft, by whichlikewise time-consuming remachining can become necessary. In addition,even minor imprecision in the anchoring area can lead, at least aftersome time, to loosening of the spring-sinker anchoring and to fracturethereof, for which reason sinker sets of the known type must becompletely replaced after a certain operating time of the machine. Thiscontributes significantly to operating costs of knitting machinesequipped with sinkers of the known type.

The object of the invention is therefore to improve a sinker of theinitially mentioned type such that with production costs which areclearly reduced nevertheless it can be built with improved quality andthus increased service life.

This object is achieved as claimed in the invention by the sinkerincluding its control springs being made as a single-piece spring steelpart, by the width (h) of the control spring, measured at right anglesto their neutral bending line on the base side of the spring on which itadjoins the sinker base body, having a larger value than on the freespring end with which the control spring can be supported on the base ofthe guide groove, and by the control spring on its base side with smoothcurvature which widens the base area adjoining the sinker base body.

The control sinker as claimed in the invention yields at least thefollowing production and functional advantages:

It can be produced very efficiently as a stamping which requires ifnecessary only very little subsequent grinding and therefore can also beproduced very economically.

The configuration of the sinker and control spring which is possible bythe integral design thereof with a configuration of the spring base areawhich widens with a smooth curvature and which also passes into thesinker base body with a smooth curvature has the advantage that notcheffects in the base area of the control spring and load-induced wear inthe area in which the spring adjoins the sinker base body can be almostcompletely prevented and thus favorably high service lives of the sinkeras claimed in the invention can be achieved.

This also applies with reference to the dimensioning of the spring widthwhich decreases from the base side of the springs to its free end, bywhich on the one hand a uniform distribution of the bending load overthe length of the control spring and on the other hand the desiredforce/spring path characteristic of the springs can be stipulated, whichyields a favorable, especially rapid (switch) response behavior of thesprings with a width in the preferred configuration of the controlspring on the support end which corresponds to between 80 and 120% ofthe thickness of the sinker material and on the base side of the springto between 150 and 250% of this thickness.

One especially advantageous configuration of the control sinker which islikewise used to achieve uniformity of the distribution of the prestressof the springs over their length consists in that the control springs inthe clearing position of the sinker runs parallel or roughly parallel tothe extended control shaft of the sinker which is provided on a middlesection of its length on its longitudinal side facing away from thespring end with the clearing foot, and in that the control spring in itsreleased configuration which it assumes before installation in thesinker carrier has a curvature which points away from the shaft with aradius of curvature which is greater than the spring length andcorresponds to 5 to 8 times the spring length, preferably roughly 6.5times.

If the radius of curvature with which the control spring smoothlyadjoins the base body and the control shaft of the sinker has a valuebetween 1.5 times and twice the value of the base width of the controlspring, for a relatively large base width thereof a notching action inthe spring base area can be reliably precluded.

In the preferred configuration of the control sinker its spring base,starting from which the smooth curvature begins with which the controlspring passes into the sinker base body and the sinker control shaftwhich projects over the support end of the spring in the longitudinaldirection, likewise with a smooth curvature, adjoins a supportprojection which points toward the free spring end, which is located onthe spring side opposite the control shaft, which proceeds from thesinker base body, and which on its side facing away from the controlspring can be supported with one obtuse-angled edge which marks one tiltaxis of the sinker on the base of the guide groove.

This yields an arrangement of the control spring base which isso-to-speak displaced into the sinker base body, and with a stipulatedsupport point of its spring end on the base of the guide groove there isa prolongation of the spring which in turn yields the possibility of afavorable stress distribution over the spring length.

For this purpose, to achieve a clearly increased service life of thespring, it is enough if length l_(b) of the control spring section nearthe base and extending between the support projection and the controlshaft of the sinker is between 7 and 15% of the spring length L'_(F),preferably around 10% thereof.

In this configuration of the control sinker it is a good idea if thebase of its control spring with the same radius of curvature smoothlyadjoins the contour edges of the control shaft and the supportprojection which run adjacent to it, parallel or almost parallel to itslongitudinal edges, to prevent undesirable notch effects it beingsufficient if the radii of curvature with which the base of the controlspring smoothly adjoins the adjacent control shaft and the supportprojection have values between the value of the base width of the springand 1.5 times the value, preferably roughly 1.1 times the value.

Other details of the invention result from the following description ofthe embodiments using the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a and 1b show alternative operating positions of a control sinkeras claimed in the invention for explanation of its operation,

FIG. 2 shows the control sinker as shown in FIGS. 1a and 1b on anenlarged scale and

FIG. 3 shows another embodiment in a view which corresponds to FIG. 2.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In FIGS. 1a and 1b, 10 labels a circular knitting machine which isrepresented by parts of its needle cylinder 11 and its cam cylinder 12and which operates with electronically controllable selection of needles13 which are used for loop formation for the purpose of achieving aprogrammably stipulated knitting pattern.

Knitting machine 10 is of that type in which needle cylinder 11 can berotationally driven around central vertical axis 14, and cam cylinder12, forming the stator of the round knitting machine 10, coaxiallysurrounds needle cylinder 11.

Needles 13 are guided to move vertically up and down over the peripheryof the needle cylinder of equidistantly distributed needle channels 16,these needle channels being made as narrow grooves which are opentowards cam cylinder 12 and which are assigned individually to needles13. In one typical design of knitting machine 10 these 2000 needles canhave needles 13 and needle channels 16 which are distributed for exampleon 40 knitting units on which one thread each is processed. The verticalup and down motions of needles 13 which are necessary for loop formationand which are superimposed on the rotational motion of the needlecylinder are controlled by sliding form-fit engagement of the radialcontrol feet of needles 13, which are not shown, with needle cam pathsof the cam cylinder 12 which are likewise not shown for the sake ofsimplicity. So that this type of motion control can take effect, needles13 participating in the knitting process are moved from a true runningposition, which is shown in FIG. 1a and which is withdrawn as far aspossible into needle cylinder 11 as the lowest position of the needles,into a knitting position which is raised compared to the true runningposition, beginning from which only the loop forming movements ofneedles 13 can be achieved which result due to the relative rotationalmovement of needle cylinder 11 relative to cam cylinder 12 by engagementof the control feet of the needles with the needle belt of cam cylinder12.

To choose in this regard needles 13 to be activated for the knittingprocess and their lifting into the initial knitting position shown inFIG. 1b, there are control sinkers 17 assigned individually to needles13 which for their part can be moved from the true running positionwhich is shown in FIG. 1a and which corresponds as it were to theinactive state of needles 13 assigned to them, into the selectionposition which is shown in FIG. 1b and which is assumed compared to thetrue running position, and in which needle 13 assigned to this controlsinker 17 is cleared out of its base running position so far that it canbe deflected in the course of the relative rotary motion of needlecylinder 11 relative to cam cylinder 12 for executing the loop-formingup and down movements of needles 13 selected at the time. This ispossible due to the form-fitted engagement of at least one radial needlepin with the guide path of cam cylinder 12 assigned to this, startingfrom the knitting position of sinker 17 which accordingly, regardless ofthe knitting deflections of needle 13 selected by it, can be guided backinto its true running position, while the return of the needle into itstrue running position is dictated by the shape of the needle cam of camcylinder 12 which is not shown.

Control sinker 17 which is shown for itself alone in FIGS. 1a and 1b inalternative operating positions within knitting machine 10 and in FIG.2, to the details of which reference is likewise made at this point, isstamped out of a spring steel strip which has a typical thicknessbetween 0.4 and 0.6 mm, to which corresponds the slightly larger insidediameter of the grooves of needle cylinder 11 which form needle channels16.

Sinker 17 with a configuration which can be taken in all essentialdetails from the scaled representation of FIG. 2 has base body 18 whichis roughly trapezoidal in its outlines and from which on the needle-sideend of control sinker 17 burr-shaped extension 19 which projects on oneside proceeds, and its needle-side transverse edge 21 which is flushwith end face edge 22 of base body 18 and with an obtuse angle which isonly slightly different from 90° adjoins sloped leg edge 23 of the basebody 18 of control sinker 17, the leg edge being located radially to theinside in the operating positions of sinker 17 shown. Transverse edge 24of burr-shaped extension 19 facing away from its needle-side transverseedge 21 adjoins roughly at a right angle radially externally sloped legedge 26 of base body 18 which includes with it radially [an angle] ofroughly 10°. This angle is slightly larger than tilt angle a (FIG. 1a)by which control sinker 17 can be tilted within needle channel 16 fromthe base running position shown in FIG. 1a into the clearing positionshown in FIG. 1b, in which radially inner sloped leg edge 23 of basebody 18 adjoins base 25 of groove-shaped needle channel 16. Pivot 27 ofthis possible tilt motion of control sinker 27 is marked by an obtuselyangled corner edge, on which radially inner sloped leg edge 23 of basebody 18 with an obtuse angle only slightly different from 180° adjoinsradially inner, linearly running longitudinal edge 28 of base section 29of control sinker 17 which is only short in its longitudinal direction.From base area 29 which also has straight boundary edge 31 on theradially outer side of the sinker, said edge with an obtuse angle onlyslightly different from 180°, marking corner edge 32 opposite pivot 27,adjoins radially outer sloped leg edge 26 of base body 18 of the sinker,there proceeds a control leg with the shape of an extended flat rodlabelled 34 throughout, its base area 36 in the radially outer part ofbase section 29 adjoins the latter and is relatively stiff, and aresiliently bendable sinker leg labeled 37 throughout, with base area 38which adjoins the radially inner part of base area 29 of base section 29of control sinker 17.

Base area 36 of control leg 34 is the sinker section which is shortrelative to length L_(S) of control leg 34, within which sectionradially outer straight longitudinal edge 39 adjoins collinearlystraight outer longitudinal edge 31 of base section 29, on the one hand,and on the other, its radially inner longitudinal edge 41 which, runningin the vicinity of base area 36 parallel to outer longitudinal edge 39of control leg 34, with semicircular contour adjoins radially outerlongitudinal edge 43 of spring leg 37, the extension of base area 36 ofthe control leg measured in its longitudinal direction corresponding toradius of curvature R₁ of curved contour 42. In a typical configurationof control sinker 17 this radius of curvature has a value of 1.5 mm.

Base area 38 of spring leg 37 is the section of the control sinker whichis short compared to length L_(F) between base 44 of spring leg 37 andits free support end 46 with which it can be supported on groove base 25of needle channel 16; within this section radially inner longitudinaledge 47 of spring leg 37 with smoothly curved outline of its radiallyinner contour smoothly adjoins radially inner longitudinal edge 28 ofbase area 29, said edge running in a straight line, and the curvedcontour area with which radially inner longitudinal edge 47 of springleg 37 smoothly adjoins radially inner straight longitudinal edge 28 ofbase area 29 has spring-side section 49 with concave curvature and basesection-side section with a convex curvature, with radii of curvature R₂and R₃ having the same size which in a typical configuration of controlsinker 17 has a value around 2 mm, two areas of curvature 48 and 51,viewed from the respective curvature center point 52 and 53, extendingover an azimuth range of roughly 45°. For the dimensions given as anembodiment this contributes to the extension of base area 38 of springleg 37 measured in its longitudinal direction corresponding roughly to1.5 times the longitudinal extension of base area 36 of control leg 43measured in the same direction.

The longitudinal extension of base section 38 of spring leg 37 which canbe compared here to its "spring" length L_(F) is distance a₁ of base 44which runs at a right angle to neutral bending line 54 of spring leg 37,from tangent 56 which runs parallel to base line 33 of base body 18 ofcontrol sinker 17 to contour area 42 which runs in a curve, with whichradially inner longitudinal edge 41 of control leg 34 adjoins basesection 29 of control sinker 17 and base section 38 of its spring leg37, contour area 48 of this base section 38 arched concavely/convexly atthe intersection point of tangent 56 with radially inner contour 47, 48,28, 23 of control sinker 17 smoothly adjoining radially innerlongitudinal edge 28 of base section 29 of control sinker 17, said edgerunning in a straight line.

Accordingly, the longitudinal extension of base section 36. of controlleg 34 which can be compared to its effective length L_(S) is distancea₂ of base line 58 of control leg 24 from tangent 56, said distancecorresponding to radius of curvature R₁.

In the "released" state of control sinker 17 shown in FIG. 2, neutralbending line 54 of its spring leg 37 in the area of its base 44 runsparallel or roughly parallel to longitudinal edges 39 and 41 of controlleg 34, the edges running for their part parallel to one another, withwhich this leg adjoins its base section 36.

Effective length L_(F) of spring leg 37 measured between spring base 44and free support end 46 of spring leg 37 which has a convex arch in thearea of its support point is slightly larger than half the effectivelength L_(S) of control leg 44 measured between its base line 58 and itsfree edge 59.

In the released state of spring leg 37 shown in FIG. 2, it has a slightcurvature which points away from control leg 34 and which has an averageradius of curvature corresponding to the contour of neutral bending line54 which has a value which corresponds to roughly 4.5 times the springlength L_(F).

Between base 44 and free support end 46 of spring leg 37 its width hmeasured at a right angle to neutral bending line 54 decreasescontinuously, leg width h_(b) on base 44 of spring leg 37 correspondingto roughly 1.8 times the value of spring leg width h_(a) on free supportend 46 of spring leg 37. One typical value of base width hb of springleg 37 at its length of roughly 32 mm and a thickness of the sinkermaterial of 0.5 mm, is 0.9 mm; on free support end 46 of spring leg 37this corresponds to a square cross section thereof.

Control leg 34 on its radially outer side has lug-shaped projection 61which points towards cam cylinder 12 and by which initial section 62 ofcontrol leg 34 which is bounded by a straight line and which proceedsfrom base area 36 of the control leg is set off against support section63 which projects over the end of spring leg 37, which has radiallyouter, i.e. pointing towards cam cylinder 12, longitudinal edge 64 whichruns from lug-shaped projection 61 to free end edge 59 of control leg 34in a straight line, with radially outer longitudinal edge 39 of initialsection 62 it includes a small acute angle of roughly 2° and in the areaof its connection to lug-shaped projection 61 relative to thislongitudinal edge 39 of initial section 62 of control leg 34 it isoffset radially to the outside by roughly width b of initial section 62.Free longitudinal edge 66 of lug-shaped projection 61 runs in a straightline and with radially outer longitudinal edge 64 of support section 63of control leg 34 includes an acute angle of roughly 1°. The middle areaof support section 63 which extends over roughly 2/5 of its length andwhich has a width b', which is somewhat smaller than the width ofinitial section 62 of support leg 34, and is roughly 80% thereofintervenes between initial area 67 of support section 63 followinglug-shaped projection 61 and the end section of control leg 34 whichforms a "radial" support foot, which is slenderly trapezoidal in basicshape, and which extends over roughly 1/3 of the length of supportsection 63.

Radially inner longitudinal edge 69 of radial support foot 68 with whichit, viewed in the true running position of control sinker 17 (FIG. 1a),is supported radially on schematically shown control magnet arrangement70, runs in a straight line and with straight radially outerlongitudinal edge 64 of support section 63 it includes an acute angle ofroughly 8°, greatest width b" of support foot 68 corresponding roughlyto 1.6 times width b' of the middle area of support section 63. Betweenradially outer longitudinal edge 64 of support section 63 and radiallyouter longitudinal edge 66 of lug-shaped projection 61 of control leg 34there extends straight support edge 71 which with radially outerlongitudinal edge 64 of support section 63 of control leg 34 joins anacute angle which in the special embodiment shown has a value of roughly68°. This "support" angle corresponds to angle of incline γ ofperipheral slide-guide surface 72 of clearing cam 73, measured in theradial plane, on which control sinker 17 with sloped support edge 71 ofits lug-shaped projection 61 which forms the clearing foot of controlsinker 17 can be supported.

In the true running position of control sinker 17 shown in FIG. 1a, inneedle channel 16 it assumes its lowest position, in which clearing foot61 is forced into needle channel 16 and with its straight longitudinaledge 66 is radially supported to slide on the cylindrical jacket-shaped,radially inner peripheral area of clearing cam 73, which while controlsinker 17 which rotates with needle cylinder 11 passes on thiscylindrical jacket-shaped, peripheral area 74, forces end section 68 ofcontrol leg 34 with its radially inner longitudinal edge 69 into contactwith permanent magnet 76 of the given knitting system of the circularknitting machine on which support foot 68 of control sinker 17 issupported to slide.

This permanent magnet 76 exerts an attractive force on support foot 68of control leg 34 which is enough to keep the control leg in contactwith the sinker against the repelling force of the control spring ofcontrol sinker 17, said spring formed by spring leg 37 and maximallyprestressed in the base running position. Control magnet arrangement 70of the respective knitting system furthermore comprises magnet coil 77,shown only schematically, which can be excited by a control current, andby whose excitation a demagnetizing field which cancels the attractiveforce of permanent magnet 76 can be produced, so that when magnet coil77 is excited, control leg 74 of control sinker 17 by the action of itscontrol spring 37 can reach the selection position shown in FIG. 1b, inwhich its clearing foot 61, projecting from needle channel 16, with itsfalling support edge 71 is vertically supported on likewise fallingslide guide surface 72 of clearing part 73 and at the same time alsoradially outer straight longitudinal edge 64 of support section 63 ofcontrol leg 34 is radially supported to slide on jacket surface 78 ofclearing cam 73, said surface being coaxial with central longitudinalaxis 14 of knitting machine 10.

Clearing cam 73, viewed in the azimuth direction, has a height whichvaries periodically by at least the amount of the stroke by whichcontrol sinker 17 can be moved up and down in needle channel 16, risingand falling as well as horizontally running sections of blade-shapedguide edge 79 of clearing cam 73 adjoining one another "smoothly,--"inan undulating manner"--.

The corresponding applies analogously to the run of the slide surface ofthe reset guide path of cam cylinder 12 on which upper end face edge 21of burr-shaped extension 19 of control sinker 17 acting as a reset footcan be supported to slide.

Selection triggering of control sinker 17 for its lifting from the truerunning position shown in FIG. 1a is possible when the control sinkerpasses by on an area of shorter height of clearing cam 73 for whichguide edge 79 of clearing cam 73, as shown by the broken line, runsunder edge corner 82 of sinker clearing foot 61 on which its slopedsupport edge 71 adjoins its free longitudinal edge 66. If in thisposition of control sinker 17 the attractive action of permanent magnet76 is cancelled by compensatory triggering of magnet coil 77, controlsinker 17 is tilted by the action of prestress of spring leg 37 aroundpivot 27, by which clearing foot 61 of the sinker reaches radially tothe outside into the position which traverses guide edge 79 and thefollowing area of slide guide surface 72 of clearing cam 73 and in whichat this point the control sinker, likewise riding with its clearing foot61 on guide edge 79 of clearing cam 73, by its relative motion comparedto the rising section of guide edge 79 of clearing cam 73 is raised intothe selection position shown in FIG. 1b. In this position of the controlsinker in which its base body 18, compared to the true running position,is tilted by angle a, and with its sloped leg edge is supported ongroove base 25 of needle channel 16, neutral bending line 54 of springleg 37 runs roughly parallel to longitudinal edges 39 and 41 of initialsection 62 of control leg 34 of control sinker 17, conversely in thetrue running position initial section 62 of control leg 34 and springleg 37 of the sinker include an acute angle with one another.

Control sinker 17' shown in FIG. 3 as another embodiment is functionallyanalogous to control sinker 17 as shown in FIG. 2 and differs from itsolely by the configuration of the transition areas via which controlleg 34' and spring leg 37' adjoin base body 18' of control sinker 17',with a configuration otherwise the same as described using controlsinker 17 as shown in FIG. 2. To the extent the same reference numbersare used in FIG. 3 as in FIG. 2 without the components of control sinker17' labelled thereby being mentioned specifically in the explanations,this should contain the reference to the description given using FIG. 2.

For control sinker 17', for purposes of explanation, it is assumed thatinstead of control sinker 17 as shown in FIG. 2 it can be used with thesame function in knitting machine 10 and accordingly the orientation andlength of sloped leg edges 23 and 26 of its trapezoidal base body 18'which has the same base width a which is measured between tilt edge 27and obtuse-angled corner edge 32 opposite it, the same configurations ofits reset foot 19, its clearing foot 61 with distances from one anothermeasured in the displacement direction of control sinker 17', and thesame arrangement of support end 46 of spring leg 37' with reference toclearing foot 61 of control sinker 17', as in control sinker 17 as shownin FIG. 2. The following details are different compared to FIG. 2 insinker 17' shown in FIG. 3:

The distance of base 33' of spring leg 37', up to which radially outerlongitudinal edge 43 and radially inner longitudinal edge 47 of thespring leg, viewed in its released state which is shown, run betweenfree support end 46 and spring base 33 with constant radius ofcurvature, from end face edge 22 of trapezoidal base body 18' of controlsinker 17', is smaller than the distances of obtuse-angled corners 27and 32 of sinker base body 19 measured from its end face edge 22. Base33' of spring leg 37' is likewise moved "into" base body 18' so that,compared to the embodiment shown in FIG. 2, there is a greater lengthL_(F) of spring leg 37' which is roughly 15% greater than length L'_(F)of spring leg 37 of control sinker 17 as shown in FIG. 2. The radius ofcurvature which is averaged between the radii of curvature of radiallyouter longitudinal edge 43 and radially inner longitudinal edge 47 ofspring leg 37' and which corresponds to the run of neutral bending line54' of spring leg 37' roughly corresponds to 6 times the length of thespring leg L'_(F).

Base width h'_(b) of spring leg 37' is only roughly 20% larger than itswidth h_(a) on free support end 46.

Obtuse-angled edge 27 which marks the pivot around which sinker 17' canbe tilted and which can be supported on groove base 25 of needle channel16 which accommodates control sinker 17' is located on supportprojection 83 which extends, measured from spring base 33', over roughly1/10 of spring leg length L'_(F) ; radially outer longitudinal edge 84of the projection facing spring leg 37' in base area 33' runs parallelto neutral bending line 54' of spring leg 37'.

Between radially inner longitudinal edge 41 of initial section 62 ofcontrol leg 34' of control sinker 17' and radially outer longitudinaledge 43 of its control leg 37', on the one hand, and between radiallyinner longitudinal edge 47 of spring leg 37' and radially outerlongitudinal edge 84 of support projection 83 of control sinker 17', onthe other, there mediate contour regions 86 and 87 which are curved in a180° arc shape with a smooth connection, which have the same radii ofcurvature which have a value of 0.75 mm in the embodiment selected forexplanation. These relatively small radii of curvature are sufficient,with the given measurements of control sinker 17' with dimensions whichotherwise correspond to those of control sinker 17 as shown in FIG. 2,to reliably preclude notch effects in base area 33' of control sinker17'.

What is claimed is:
 1. Control sinker for selection and control ofloop-forming motions of knitting implements of a knitting machinecomprising a plurality of control sinkers assigned to respective ones ofsaid knitting implements, each of said plurality of sinkers having aform of a stretched flat bar for use as a control element in saidknitting machine that can be deflected in a guide groove of a sinkercarrier of the knitting machine in the longitudinal direction of saidguide groove in alternative directions, wherein said sinker carrier ofsaid machine comprises a plurality of said guide grooves runningparallel to one another and located equidistantly next to one another,for holding one control sinker at a time, with driving thereof takingplace by relative movements of the sinker carrier and a cam carrier ofsaid knitting machine, said cam carrier having a clearing cam with aclearing edge that with said relative movements passes by the controlsinkers on contour edges of lug-shaped clearing feet of said controlsinkers, said edges running transversely to said longitudinal sinkerguide groove direction, for controlling deflections of the controlsinkers, and the control sinkers each having a control spring proceedingfrom a base body of the respective sinker, said base body having theshape of a stretched rod, and wherein said control spring has a free endwhich is supported to slide on the base of the guide groove for thecontrol sinker in said sinker carrier, and said control spring beingprestressed such that the clearing feet of the control sinkers aredisplaced into a clearing position of drive engagement of their clearingfoot for transferring deflection driving, with the clearing edge of theclearing cam of the cam carrier, furthermore the control sinkers aredisplaced by control elements of the cam carrier and sinker carrier fromsaid clearing position into a base position where the drive engagementof their clearing feet with the clearing edge of the clearing cam isinterrupted, in this base position the sinkers are fixed by theretaining force of a permanent magnet arrangement of said knittingmachine and are released by compensatory triggering of an electronicallycontrollable magnet arrangement of said knitting machine for passageinto the clearing position, and wherein said control sinker includingits control spring is made of a single-piece spring steel part, a widthof said control spring, measured at right angles to a neutral bendingline of said control spring in a released state, on a base side of thespring adjoining said sinker base body, has a larger value than on saidfree end thereof where said spring is supported on a base of its guidegroove, and wherein said spring on its base side adjoins the sinker basebody with smooth curvature which widens the base area of said spring. 2.Control sinker as claimed in claim 1, wherein said width of said controlon said free spring end thereof is between 80 and 120% and on its baseside is between 150 and 250% of the spring thickness.
 3. Control sinkeras claimed in claim 1, wherein said control spring in the clearingposition of the sinker runs parallel to a stretched control shaft of thesinker, said control shaft having a clearing foot on a middle section ofits length on its longitudinal side facing away from said controlspring, and said control spring having in its released state aconfiguration with a curvature in a direction away from said controlshaft, a radius of said curvature being greater than the length of saidcontrol spring.
 4. Control sinker as claimed in claim 3, wherein theradius of curvature of said control spring has a value which is between5 and 8 times the spring length.
 5. Control sinker as claimed in claim3, wherein the radius of curvature with which the control springsmoothly adjoins the sinker base body and the control shaft of thesinker is between 1.5 times and twice the value of the base width of thecontrol spring.
 6. Control sinker as claimed in claim 3, wherein saidcontrol spring base, starting from which said smooth curvature beginswith said control spring adjoining said sinker base body, wherein saidcontrol shaft of said sinker projects over the free spring end of saidspring in the longitudinal direction, and wherein a further smoothcurvature adjoins a support projection pointing towards said free end,of said control spring and located on the side of said control springopposite said control shaft, and proceeding from said sinker base body,and wherein on the side of said projection facing away from the controlspring said projection having an obtuse-angled edge which marks a tiltaxis of the sinker for supporting said control spring on the base of itsguide groove.
 7. Control sinker as claimed in claim 6, wherein a lengthof a section of said control spring near the base and extending betweensaid support projection and said control shaft of said sinker is between7 and 15% of the length of said control spring.
 8. Control sinker asclaimed in claim 6, wherein said base of said control spring smoothlyadjoins contour edges of said control shaft and said support projectionwith curvatures having the same radius of curvature which run adjacentto it, parallel to longitudinal edges of said control spring.
 9. Controlsinker as claimed in claim 6, wherein the radii of curvature of saidsmooth curvatures with which said base of said control spring smoothlyadjoins adjacent control shaft and the support projection of said sinkerhave values between the value of the base width of said control springand 1.5 times said value.